Method of conditioning fabrics



y 5, 1969 I c. J. GAISEIR 3,442,692

METHOD OF CONDITIONING FABRICS Filed Aug. 15, 1965 INVENTOR. CONRAD J.6A lSER BY/Mi. g

ATTORNEY United States Patent 3,442,692 METHOD OF CONDITIONING FABRICSConrad .I. Gaiser, 6009 Seaside Walk, Long Beach, Calif. 90803 FiledAug. 13, 1965, Ser. No. 479,590 Int. Cl. B44d 1/46 U.S. Cl. 117-120 8Claims ABSTRACT OF THE DISCLOSURE Fabrics are conditioned by comminglingthe same in a laundry dr-yer by tumbling them together with a flexiblesubstrate carrying a softening or other modifying agent whereby theagent is transferred to the fabrics.

This invention relates to the conditioning of fabrics by well knowntypes of fabric conditioners such as softening, antistatic, lubricating,bacteriostatic, mildew proofing or moth proofing agents, or agents thatmay impart several properties to the fabric, such as softeners whichalso im part antistatic properties.

In laundering, it is common to treat various types of household andgarment fabrics, such as wool, cotton, silk or nylon, with agentsselected from among the above types to render them soft to the touch andto reduce knotting or wrinkling, and thus facilitate ironing, or torender them free of static, bacteria resistant, to deodorize them orotherwise to condition them. In commercial laundries, this is usuallydone by introducing a solution or dispersion of the agent fromcontainers during the washing cycle or during rinsing of the fabric withfresh water after it has been washed, particularly in the last rinsingstep.

As a result of prior laundering, residual soaps and detergents arepresent on the fabric. Because the fabric conditioning agents of thecharacter described above are generally cationic and hence arechemically incompatible with the occluded soaps and detergents which areanionic, the fabric conditioning agents suffer loss of eifectiveness bymutual precipitation in contact with the residual soap or detergent.Thus, even though it has been the practice to add the agent at the startof the last rinsing step, there is still detergent or soap presentespecially in the home laundry, and consequently there is no assurancethat an etfective amount of the agent will remain on the fabric.

Moreover, when the agent is applied from a liquid dispersion orsolution, this is uneconomical because the conditioning agents require16 to 20 times as much solvent, usually water or water-alcohol mixtures,than agent; and this increases shipping and handling costs entailed bythe relatively large quantities of solvent that have to be handled.Also, the container and bottling costs are relatively high, andexcessive quantities of the liquid containing the agent have to beemployed, to render the agent effective.

The present invention is designed to overcome the foregoing problems.Summarizing the same, it comprises incorporation of such type of agentuniformly in a fabriclike substrate, felted or Woven, such as papertoweling or scrirns, swatches of cloth or absorbent sponge, which may bereadily handled and shipped or transported in the dry state. A sheet ofthe substrate carrying the agent is advantageously placed in anyconventional laundry dryer together with washed but still wet fabricwhich is usually in the form of sheets, garments, pillow cases, etc.,and has been thoroughly rinsed so as to be substantially free ofdetergents or soaps, having gone through the complete wash and rinsecycle. In the rinse cycle, the fabric is rendered damp, although stillwet, by centrifugal spin drying.

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In the drying cycle, the current of heated drying air or otherheatedinert gas, and water vapor which evolves from the fabric, causethe agent to vaporize from the substrate and deposit or condenseuniformly on the fabric, as the pieces of fabric and the substrate arebeing simultaneously tumbled or agitated by the internal ribs of therotating drum or wheel in a conventional laundry dryer. This tumblingaction causes the substrate to commingle with all pieces of the washedfabric, thus resulting in all of the fabric pieces being exposed to theagent. Although not as effective because of substantial presence ofaforementioned residual soaps or detergents from the washing or rinsingcycle, the substrate carrying the conditioning agent can be introducedoptionally during the washing cycle or during any of the rinsing cycles,desirably the last rinse step, and it will still effectively transfersome of the agent to the pieces of wet fabric.

Incorporation of the agent into the substrate can readily be etfected bycoating a sheet of the substrate with a liquid solution or dispersion ofthe agent, as by immersion, or by spraying, wringing or pressing out theexcess, and then drying the substrate to leave it uniformlyimpregnatedwith the agent. The substrate is desirably in the form of cellulosicsheet material, such as conventional perforated paper roll toweling, orin the form of packaged swatches of either paper toweling, or fabricsuch as flannel, which can be removed one at a time from the package. Aspecial advantage is that by virtue of its simplicity, the impregnatedsubstrate can be readily used by the housewife in the household inconventional laundry and drying appliances, under conventional operatingconditions, as well as in commercial laundries.

From the preceding, it is seen that the invention has as its objects,among others, the provision of an improved, simple and economical methodand product therefor, for conditioning fabrics by agitating andthoroughly commingling the same with a substrate carrying a conditioningagent for the fabric in a stream of heated gas and water vapor, andwhich method and product can advantageously be employed in the dryingcycle wherein the fabric is substantially free of soaps or detergents.Other objects will become apparent from the following more detaileddescription.

Reference will now be made to the accompanying single sheet of drawingwhich is a schematic elevational view of a !well known type of householddryer, for a more detailed description of the invention; a portion ofthe structure being shown broken away.

Any type of conventional conditioning agent heretofore used in theconditioning fabrics can be employed. Such agents are presently marketedas solids, pastes, or liquids as in aqueous or aqueous-alcohol solutionor in dispersion form, and they are generally cation-active substances.The substrate is impregnated with such agent as by immersion in asuitable liquid solvent containing the agent, and subsequently removingthe agent by evaporation. In the dryer, the agent is distilled from thesubstrate and redistributed by the heat of the drying gas current andthe water vapor leaving the fabric being dried, and subsequently isdeposited uniformly on the fabric or fabrics being dried.

As illustrated in the drawing, all that need be done is to introduce arelatively small sheet 2' of the substrate carrying the conditioningagent, into a conventional dryer chamber or enclosure 3 having aconventional rotatable dryer drum or agitator 4 and door 6, and in whichribs 7 on the drum elfect thorough commingling of the pieces of washedbut damp fabric 8 with the substrate. Vent 9 is provided, allowingescape of drying gas and water vapor.

The normal drying time of about 40 to 60 minutes and the normal dryingtemperatures of about F. to F. commonly employed for laundry drying taresatisfactory. By the time the fabric pieces have been dried most of theconditioning agent has been transferred from the substrate to the fabricand is uniformly deposited thereon. After the conditioning treatment,the dried pieces of fabric are removed from the dryer and handled in thecustomary manner, such as ironing. v

Compounds which act as conditioning agents fall into two classes, thosepractically useful and those impractical to use. The followingdiscussion describes the practically useful class of these compounds,all of which function because of their substantivity to fabrics. For thepurpose of this invention, these are collectively described as fabricconditioning agents, and it is not the intention tolimit this inventionto any specific agent or chemical species.

The most effective fabric conditioners are cationics. However, someanionics such as calcium and magnesium salts of ordinary fatty acids of14 to 18 carbon atoms chain length are also effective but turn yellowwith age. Some of the amphoteric molecules are also effective, probablybecause their positive charge attaches them to the fabric. Specifically,the requirements for a fabric softener are, (1) one or more hydrophobicside chains of 14 to 18 carbon atoms in chain length; and (2) apositively charged end to serve as a point of attachment to thenegatively charged molecule of the fiber.

Typical fabric conditioners include:

(a) Primary, secondary, and tertiary amines and their water soluble orwater dispersible salts. For example:

where R and/or R may be an alkyl group of 16 to 18 carbon atoms or anyequivalent group with comparable hydrophobicity.

(b) A quaternary nitrogen-containing base or salt. For example:

2 i -Ra) where X may be any one of the following groups: OH- Cl- Br- HSOS0,,- or similar negative radieles, and where R and R may be as in (a)above and R and R are methyl or ethyl groups.

() Alkyl imidazolines and imidazoles.

(d) Alkyl pyridine and piperidine salts.

(e) Alkyl sulfonium salts.

(f) Alkyl phosphonium salts.

(g) Esters of amino acids.

(h) Esters of amino alcohols.

(i) Alkyl guanidines and their salts.

All of the above are effective as softening agents. Effective softeningand antistatic agents are quaternary ammonium chlorides or bromides, andalkyl imidazolinium chlorides or bromides. Suitable as antistatic agentsare alkyl dibenzyl ammonium chlorides and alkyl amines. Alkyl dimethylbenzylammonium chlorides and dodecyl trimethyl ammonium chloride aredesirable bacteriostatic agents.

As previously related, it is immaterial what the conditioning agent isas long as it is substantive to the fabric upon which it is deposited,and will vaporize under the flow of drying air and steam generated fromthe washed fabric as it is being dried.

The amount of conditioning agent incorporated in the substrate should besufficient to be effective, while substantial excess thereof, serves nopurpose, and is thus uneconomical. The actual amount is variable anddepends on the characteristics of the agent employed. About 1.0 to 10.0grams of the agent carried in a sheet of approximately 105 square inchesof dry conventional paper toweling or flannel fabric, introduced intothe dryer with the fabric to be dried, will usually suffice for thenormal 4 household dryer in which the usual load of 5 to 10 lbs. offabric is dried in about 40 to 60 minutes under normal drying conditionsof about 120 F. to 190 F. In commerical laundries having greater dryercapacity, more substrate sheets carrying the agent are proportionatelyincorporated with the fabric pieces in the dryer.

All of the aforementioned agents are soluble or dispersible in water orin water-alcohol (desirably isopropyl alcohol for economy) solvents. Toincorporate the same into the woven or felted substrate, all that isrequired, as previously related, is to immerse the substrate in asolution or dispersion of the agent having a concentration sufficient toprovide the desired amount of agent on the substrate, or to coat thesubstrate with the liquid carrying the agent by any conventional coatingroll applicator which meters the coating onto the substrate, and thenremove the solvent from the substrate by drying either at ambienttemperature or by oven drying. The resultant treated substrate can thenbe distributed in perforated roll form from which individual sheets canbe readily detached, with each sheet carrying a desired predeterminedamount of agent, or it can be packaged in the form of a stack ofindividual separated sheets each carrying such amount of agent.

EXAMPLE I As a typical example illustrative of the invention, aconventional paper towel of about square inches in size was immersed andsqueezed in a dispersion of 2.0 grams of dimethyl, di(hydrogenatedtallow), ammonium chloride (a quaternary ammonium compound known asArquad 2H-D-75" by Armour Chemical Company) in 7.0 cc. of water and 1.5cc. of isopropanol, prepared at 18 C. After all the liquid had beenabsorbed, and the paper towel was dried at ambient temperature, 2.0grams of the agent were distributed uniformly in the substrate. Such drysubstrate carrying the agent was then introduced into a conventionalhousehold clothes dryer (Kenmore gas dryer) with an approximate 8 lb.load of damp fabrics (towels and linens) which had been spin-dried bycentrifugation in the washer. During a conventional drying cycle ofabout 50 minutes under conventional drying temperature of about 150 F.,the substrate was thoroughly tumbled around with the fabric by thedrying agitator.

During such treatment, sufiicient of the agent vaporized from thesubstrate into the carrier gas stream, namely, heated air and steamgenerated from the fabric, and deposited on the fabric pieces renderingthem notice ably softer, antistatic and fluflier. In the dryer, theimparted lubricating effect and the freedom from static reduced knottingand binding thereby substantially reducing wrinkling. The antistaticqualities remained with the fabric pieces until they were rewashed, thusrendering them more comfortable to wear; and because of the softening,the need for ironing was minimized and ironing was made easier.

EXAMPLE II 50 grams of the aforementioned quaternary ammonium compoundof Example I, were dispersed in 15 cc. of isopropyl alcohol and 70 cc.of water at 75 C. Ten conventional sheets of perforated paper toweling,each of square inches were folded along the perforations into a padwhich was pressed into this dispersion, and was squeezed and workeduntil all the solution was evenly dispersed throughout the pad.

The pad was then unfolded and hung on a wash line to dry. Drying tookabout 10 hours at ambient temperature. After the drying, the impregnatedsheets were very flexible, transluscent and had a waxy feel. Checkingthe dry weight of the towels established that each sheet had picked upapproximately 5 grams of the conditioning agent.

Over a period of several weeks, these impregnated towels were employedfor conditioning fabrics by adding one towel to a conventional gasheated (Kenmore) clothes dryer with each load of approximately 8 lbs. offreshly laundered clothes to be dried; the drying tempera ture beingabout 150 F., and the time about 50 minutes. After the drying, theclothes were removed and in each instance were softer, had fewerwrinkles, showed no electrostatic charge .and ironed more easily. Eachremoved paper towel was intact, and had lost about 80 percent of theagent. In such condition, it was found useful as a dust cloth to rendersurfaces, such as phonograph records, antistatic.

In the case where the conditioning agent is a softening agent only or asoftening and antistatic agent combination, the substrate therefor neednot be discarded after the drying cycle because there still remains asufiicient amount of the agent thereon which enables the substrate to beemployed advantageously as a dusting or cleaning cloth, particularlyWhen the substrate carrier is of relatively soft material such asflannel.

I claim:

1. The method of conditioning fabrics which comprises commingling piecesof damp fabric by tumbling said pieces under heat in a laundry dryertogether with a flexible substrate carying a conditioning agent toeffect transfer of the conditioning agent to the fabric while beingdried.

2. The method of claim 1 wherein the substrate is paper.

3. The method of claim 1 wherein the substrate is cloth.

4. The method of claim 1 wherein the agent is a softening and antistaticagent.

5. The method of claim 1 wherein the agent is an antistatic agent.

6. The method of claim 1 wherein the agent is a bacteriostatic agent.

7. The method of claim 1 wherein the substrate is a dry paper sheetcarrying an amount of agent of about 1.0 to 10.0 grams per squareinches.

8. The method of claim 1 wherein the fabric pieces are rinsedsubstantially free of detergents or soaps and rendered damp bycentrifugal spinning thereof prior to being dried in said laundry dryer.

References Cited UNITED STATES PATENTS 2,734,830 2/ 1956 Hagge et a1.3,033,704 5/ 1962 Sherrill et a1. 3,227,614 1/1966 Scheuer 117-138.5

ALFRED L. LEAVITT, Primary Examiner.

J. A. BELL, Assistant Examiner.

US. Cl. X.R.

